Patients who undergo certain procedures, such as a spinal fusion, may have pedicle screws placed into their vertebrae. The pedicle screws are typically implanted into the vertebrae through the pedicles of the vertebrae. Once a pilot hole is created through the cortex of the bone, a probe is used to create the path through which the pedicle screw will be placed into the vertebrae. Placing the pedicle screw at the correct angle helps to assure a mechanically sound construct and to avoid injury to surrounding structures such as the spinal cord, nerve roots, and blood vessels. The orientation of the screw can be described in two planes: (1) the transverse plane, which is parallel to the ground if the person is standing upright, and (2) the sagittal plane, which divides a person into left and right halves.
To assist surgeons to properly place and orient a pedicle screw in a vertebra, a variety of machines have been used. However, these machines are typically costly and bulky, thereby reducing the number of available surgical suites that have suitable equipment for use in assisting a surgeon with properly placing and orienting a pedicle screw. Therefore, further developments in medical technology are needed so as to enable physically smaller, cost effective devices that provide the desired level of assistance to surgeons.